Error Message: Server Response code 504.

This error message is displayed if access to port 443 is blocked.

Our software needs this port open so it can communicate with the server.  Please check with your company’s network engineers that this port is open.

If your network administrator does not allow traffic on this port then you can use port 80 instead.

Follow these steps
  1. use the ‘Remove Keystore’ option from Windows Start menu >> All Programs >> Locklizard >> Lizard Safeguard >> Viewer >> Remove Keystore.
  2. copy and paste the license file link into the browser address bar and change the HTTPS to HTTP.  Then press enter.If the error message still occurs then ask the document owner to send you a license file that uses HTTP.  Remove your keystore, then double-click on the new license file to register.